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Volga Baikal AGRO NEWS Update on the Latest Scientific Discovery !!!
Impact of the carbon dioxide on the photosynthesis of plants:
Corn and other crops are not adapted to benefit from elevated carbon dioxide levels.
Carbon dioxide (CO2) levels continue to rise. Plants are able to use CO2 through photosynthesis to generate productivity. Logically, much CO2 in the atmosphere should drive better crop yields. However, a new survey from the University of Illinois shows that some crops, including corn, are adapted to a pre-industrial environment and cannot allocate efficiently their resources to get benefits from the additional carbon dioxide production. But that can be changed!
Most plants (including soybeans, rice, canola, and all trees) are classified as C-3 group because they bind CO2 into a carbohydrate containing three carbon atoms.
Corn, sorghum, and sugarcane belong to a different group known as C-4 group, so-called because they convert CO2 to a four-carbon carbohydrate during photosynthesis.
On average, C-4 crops are 60 % much more productive than C-3 crops.
Researchers at the University of Illinois, in their work, supported by the Water Efficient Sorghum Technologies (WEST) project to develop bioenergy crops, reviewed the relevant literature, examined experimental data, and came to the following conclusion:
When crops were grown in laboratories under high CO2 conditions imitating atmospheric conditions, C-3 crops did show an increase in fertility, but C-4 did not.
“As scientists, we need to think a few steps ahead to anticipate how the Earth will look like in five – thirty years, and how the crop yields will grow or drop in the new environment,” – says Charles Pignon, participant of the work. “We decided that a literature review and a retrospective analysis of the biochemical limitations of photosynthesis could give us some insights why C-4 crops don’t respond properly and how we can change it.”
The team assembled a dataset of photosynthetic measurements of 49 species of C-4 group, including crops that could reveal limitations in photosynthesis.
The pattern found was that at low levels of CO2 – much more lower before the industrial revolution – the photosynthesis of C-4 plants was the extent of the activity of the ferment fixing CO2.
However, at today CO2 level, the photosynthesis of C-4 plants is limited by its ability to provide a three-carbon molecule which takes the fourth CO2.
“This discovery is analogous to a production line for assembling cars, where we install an engine first, and only after that – wheels,” – says Stephen Long, co-author of the research article. “Our goal is to design such plants which will use their resources in the best way.”
First of all, the authors suggest C-4 crops have to reduce the amount of the ferment used to fix CO2 and reinvest the resources saved in the foundation more molecules of the CO2 acceptor.
Secondly, it is necessary to limit the penetration of CO2 into the leaf of the plant reducing the number of pores (stomata) on the leaf surface. “Reducing the CO2 content in the leaves will re-optimize biochemistry without reducing the rate of photosynthesis, and with fewer stomata, less water is lost, so we will increase the efficiency of the water use by a plant,” – says Stephen Long.
The WEST project was over in 2019. These changes proposed are testing currently on the to C-4 crops at the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), which is supported by the United States Department of Energy.
